Coassigned application Ser. No. 840,389, filed Oct. 6, 1977, now U.S. Pat. No. 4,169,719, issued Oct. 2, 1979, described herbicidal sulfonamides prepared by reacting an appropriate 2-aminopyrimidine with an appropriately substituted sulfonyl isocyanate or isothiocyanate. The described sulfonamides are active herbicides and are especially useful in controlling nutsedge in crops such as cotton, corn, rice and wheat.
The development of an attractive process for preparing the above described sulfonamides by necessity involves finding inexpensive, easily employed processes for preparing the pyrimidine and isocyanate or isothiocyanate intermediates. The pyrimidine intermediate has been difficult to prepare due to hazards associated with raw materials and waste streams. Thus, any simplification in the preparation of the pyrimidine intermediate is desirable.